1. Field of the Invention
The present invention relates to providing global positioning system (GPS) position information, and more particularly, to a system and method of providing position information by using a wireless network such as a wireless personal area network (WPAN).
2. Description of the Related Art
A GPS is a system providing positioning, speed, and time information services by using satellites. The GPS can accurately provide 3-dimensional position, altitude, and time information services and can provide such services continuously for 24 hours a day. The GPS has several advantages in that the information services are robust against weather conditions, interference, and interruption, and a common coordinate system can be utilized around the world. A user can get accurate position information by simply installing a dedicated receiver in the same manner as a conventional radio navigation system.
Typically, a GPS signal has a low energy density because such a GPS signal is transmitted from a satellite and is spread over a wide area. Since an antenna receiving the GPS signal is omni-directional, it is difficult to expect an antenna gain of the GPS signal for the antenna. Furthermore, the frequency of the GPS signal is equal to or higher than 1 GHz, and attenuation of the GPS signal becomes greater at a coaxial cable connecting the antenna and a GPS receiver.
In order to correct the attenuation in the GPS signal and to reduce noise in the antenna of the GPS receiver, a low noise amplifier (LNA) with a 20˜40dB gain is embedded in the antenna or a frequency conversion circuit that is a part of the GPS receiver is used. However, a power source required inside the antenna or a local oscillation frequency signal for frequency conversion overlaps in the coaxial cable connecting the antenna and the GPS receiver. As a result, antennas other than the specified antenna for the GPS receiver cannot be used in usual cases.
Accordingly, it is almost impossible to receive the GPS signal in a closed space or an indoor place where the GPS signal becomes weak or absent. In order to enable reception of the GPS signal, the performance of the antenna, the low noise amplifier (LNA), and the GPS receiver should be greatly improved. Unfortunately, such hardware improvements can be cost prohibited.